Kafka + Zookeeper: Connection to node -1 could not be established. Broker may not be available

UPD: if you are running in single-node mode:

I have seen this message in spark console log while trying to deploy application. Solved by changing this parameter in server.properties:

listeners=PLAINTEXT://myhostname:9092

to

listeners=PLAINTEXT://localhost:9092

make sure that you have java process listening on 9092 with netstat -lptu